diff -u b/core/modules/migrate/src/Plugin/IdAuditingMigration.php b/core/modules/migrate/src/Plugin/IdAuditingMigration.php
--- b/core/modules/migrate/src/Plugin/IdAuditingMigration.php
+++ b/core/modules/migrate/src/Plugin/IdAuditingMigration.php
@@ -2,10 +2,19 @@
 
 namespace Drupal\migrate\Plugin;
 
+use Drupal\Component\Plugin\Exception\InvalidPluginDefinitionException;
 use Drupal\Core\StringTranslation\TranslatableMarkup;
 
-class IdAuditingMigration extends Migration {
-
+/**
+ * Class IdAuditingMigration
+ *
+ * @package Drupal\migrate\Plugin
+ */
+class IdAuditingMigration extends Migration implements MigrationIdAuditInterface {
+
+  /**
+   * {@inheritdoc}
+   */
   public function audit() {
     $conflict = [];
 
@@ -23,8 +32,10 @@
         $arguments = $label->getArguments();
         $conflict[$base_id] = isset($arguments['@label']) ? $arguments['@label'] : $label->render();
       }
+      return $conflict;
     }
-    return $conflict;
+
+    throw new InvalidPluginDefinitionException($this>$this->getPluginId());
   }
 
 }
diff -u b/core/modules/migrate_drupal/src/Plugin/migrate/FieldMigration.php b/core/modules/migrate_drupal/src/Plugin/migrate/FieldMigration.php
--- b/core/modules/migrate_drupal/src/Plugin/migrate/FieldMigration.php
+++ b/core/modules/migrate_drupal/src/Plugin/migrate/FieldMigration.php
@@ -8,7 +8,6 @@
 use Drupal\migrate\Plugin\IdAuditingMigration;
 use Drupal\migrate\Plugin\MigrateDestinationPluginManager;
 use Drupal\migrate\Plugin\MigratePluginManager;
-use Drupal\migrate\Plugin\Migration;
 use Drupal\migrate\Plugin\MigrationPluginManagerInterface;
 use Drupal\migrate\Plugin\RequirementsInterface;
 use Drupal\migrate_drupal\Plugin\MigrateCckFieldPluginManagerInterface;
diff -u b/core/modules/migrate_drupal_ui/src/Form/MigrateUpgradeForm.php b/core/modules/migrate_drupal_ui/src/Form/MigrateUpgradeForm.php
--- b/core/modules/migrate_drupal_ui/src/Form/MigrateUpgradeForm.php
+++ b/core/modules/migrate_drupal_ui/src/Form/MigrateUpgradeForm.php
@@ -3,6 +3,7 @@
 namespace Drupal\migrate_drupal_ui\Form;
 
 use Drupal\Core\Datetime\DateFormatterInterface;
+use Drupal\Core\Entity\ContentEntityBase;
 use Drupal\Core\Form\ConfirmFormBase;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Render\RendererInterface;
@@ -459,7 +460,7 @@
       if ($migration instanceof IdAuditingMigration) {
         $audit = $migration->audit();
 
-        if ($migration->getDestinationPlugin()->isTranslationDestination()) {
+        if ($migration->getDestinationPlugin() instanceof ContentEntityBase && $migration->getDestinationPlugin()->isTranslationDestination()) {
           $i18n += $audit;
         }
         else {
only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/migrate/src/Plugin/MigrationIdAuditInterface.php
@@ -0,0 +1,25 @@
+<?php
+
+namespace Drupal\migrate\Plugin;
+
+/**
+ * Interface for auditable migrations.
+ *
+ * These migrations's IDs will be audited. This means that, for the entity type
+ * this migration creates, if the highest destination ID is greater than the
+ * highest source ID, a warning will be displayed that entities might be
+ * overwritten.
+ */
+interface MigrationIdAuditInterface {
+
+  /**
+   * @return array
+   *   A key/value pairing of the entity type and its label or empty array if
+   *   there are no conflicts.
+   *
+   * @throws \Drupal\Component\Plugin\Exception\InvalidPluginDefinitionException
+   * @throws \Drupal\migrate\MigrateSkipRowException
+   */
+  public function audit();
+
+}